Train-stopping device.



H. G. SEDGWICK.

TRAIN-STOPPNG DEVICE. APPLICATION FILEII Nov. 22. I9I2. IIENEWED MAY II, 1915.

Patented Dec. 21, 1915,.

i i III MWI VIN. l

G. SEDGWICK, 0F MILL` VALLEY, CALIFORNIA, ASSIGNOR TQy THE NATIONAL SAFETY lAIEIEIJIKANCIJ COMIANY, .A COBPDRATION OF'CALIFOBNIA.

TRAIN-'sroPPINe nnvrcn f specification of Letters Patent. Patented nec, 21911915 application fusa november a2, 1era, serial No. 732,985. Renewed may 17, 1915. serial 110.28371.

'To all 'whom z't may concern:

p Bc it known that I, HIRAM G.'Snocw1on, a citizen of the' United States, and a resident of Mill Valley, county of Marin, State of California, have invented certain new and useful Improvements in Train Stopping Devices, of which lthe following is a full and clearv specification, reference being had to .the accompanying drawings, in whichis l represented a vertical longitudinal sectionalview of my.' improved valve apparatus.

The object of this invention is to provide la simple pneumatic'apparatus which will be controlled and operated. by fa fluid pressure source pn ne ofthe vehicles of the train; the, prefer d construction being such that said vHuid pressure will be utihzedto not only normally hold the brake setting devices out of action but will .also serve to Oactuate the brake setting devices/when the brake is to be applied. I 'have illustrated myl fluid ressure motor mechanism as applied to a rake setting vent valve for a-ir brakes but it will be understood that in its broadest as-A ectsV the invention includes the idea of cominin my motor with anytype of brake setting evice's, even an electric braking means. further object of the invention is to lso construct the apparatus that I avoid the use of all stuliing boxes, which are undesirable in view ofthe fact that unlessfthe apparatus isy frequently used the packings stick and thus endanger the proper operation of the apparatus.

In the drawing, ,a designates a'small pipe which at its end-'is provided with a" vent Mvalve b which is adapted to be operated in l any suitable manner by the automatic mechmnism which coperates with the road bed actuating means..l An instance of Oneway et actuating this valve o is illustrated in',

co-pending application Serial'Number "M5,

162. This pipe a is connected'at its upf per end tothe left hand end of the cylinder c 1n which operates a piston valve d. This 'piston valve is preferably constructed as shown with a pair of cup leathers. At the right hand end of cylinder c is a smaller cylinder e which is open at its left hand end to the cylinder d and at itsfright hand end to the atmosphere. In this cylinderc works another `piston valve fr. which is connected by a stem g to the piston cZ. A port h extends axially through the stem vg and connects at its inner end with a radial port 'z' formed in the piston d.

The port e' connects, when the piston l is 1n its normal position, which is the position shown' in the drawing, with a port which extends to the right hand end of cy inder c serving as a head for the cylinder lc.

Another port Z is formed in the cylinder c and communicates withthe interior thereof atopposite sides of the pistond when the vsame 1s in normal position. This port Z extends through the Wall of the cylinder la to va .port m whichV is in communication with the main air reservoir n by a pipe o, whereby a main reservoir pressure is constantly exerted on both sides of piston d. A port p extends from inlet m'to the left hand end of cylinder is, and this port p is regulated asv to 'area tty means of a screw valve g.

The left hand end of cylinder Ic is closed by ahead r and this head is provided with a cylind r s, one end. of which opens to the at hand end of cylinder 7c; the interior of this cylinder at the right of the piston being in communication with'the atmosphere through portsj, z' and k.

Connected to piston t and itting cylinder s is a tube lw which is provided with a vending slot or slit w extending longitudinally'of Vit and also with one or more vent holes y at suitable points along the length of the tube.

The end of the tube opposite thepiston t is provided with a painof pistons a and b', the former being slightly larger than the latter. The piston b', is practically equalvin diameter to the tubew and is attached to the extreme end thereof, while the piston a is a littlelarger and is supported a short dis'- tance, in. front of the piston t" `by means ofa rigid connecting rod c smaller in diameter than the tube fw. The piston a works in a cylinder Z .at a point beyond a port e which is connected to the air brake pipe by means of pipe f", so that train pipe pressure is always maintained in the smaller chamber between the two pistons a .and b. lThe inder d' and serves' to closethe sain'e'ivhile the Piston ai" 010595 thevother end .of the cyl-*- inder ci. The'piston b. being less in diame` ter than the bore of cylinder d', When said piston together with tube *fw is pushed into 'cylinder d', the brakev pipeis vented throuy hA the slot min the tubew; thus applying t 1e .train brake. The use of a slot a: in the tube insures a gradua'lor service, application of' the brakes.

The fluid pressure reservoir n 1s munication with the left hand end of cylin dere 4by means of a pipe 'g' and the aforesaid pipe 0;, a check valve la being employed at the juncture of. these two pipes. rl/he valve" it is adapted tobe opened manually so as to permit main reservoir pressure t0 be ad`- mitted into pipea. When the main reservoir pressure hasthus been admited into pipe ai all the parts will assume the positiozrshown in' the drawing and the brake setting mechanism Will bereadyor actuation, Whiohwill occur when valve bis opened to exhaust or partially exhaust the front-end ofcylinder c through pipe a." y

When the valve Z is opened, the reduction in pressure in the forward end of cylinder 0 permits reservoir pressure'to quickly throw piston d forwardly. This forward move-4 ment, instantly closes the forward branch of port Z andthus cuts of reservoir pressure from in front of piston (l, and this move- 'ment also cuts cd the rear end of cylinder 7c,

by closin g port y y', from the atmosphere.

Fui-ther movement of piston'd puts the rear i end of cylinder c in communication With the rear end of cylinder it tliorugh port j, Whereupon reservoir pressure will enter behind .screw valve g. As this forward movement A'taires place the piston b will pass into the cylinder d and thusexhaust the train or y brake pipe j" out through one or more'oisthe.

ports :r and y. 'The speed With which tliex- .v haust slot s' enters the tube d will determine the time period for applying-the brakes of the train. I prefer using the lo'ig narrow .slot port ai whenv this invention iszapplied to an ail" brake system since in that mann'er I `To restore the' parts to normal position, it" u iS Simply necessary to open check valve providewor a service' application of' the .brakes as distinguished from an emergency stop. .Y

to permit reservoir pressure to enter the foi'- Ward end of' cylinder c, whereupon all the parts vvillyreturn to normal through the nieuwe! pushing-esther; its back a alarm emi of this-cylind 'andthe venting ofthe rear end of cylinder c ,through ports j, z' and k.

It .will be observed-thereforethat Iv employ main `reservoir 'pressure forolding the brake setting means-in position for actuation and also for positively actuating said brake setting means.` The advantage of using the pilot dltierentialv valve' devices (consisting of thetpiston i and its cooperating parts) isa that the `mechanism may be vput into operation `by-x'll-.the venting of but a very small` in odicuml of air, since it will' require but a very little air to be exhausted from the forward 'part of cylinder c to shift the pre dominatingpressure to the rear side of pis' ton d.

, It. will'be observed also that with the pres- I i i entapparatus it is unnecessaryto use stui'- ingr lboxes at anyvpoint, these stu'ngfboxesI belng undesirable in that unlessfrequently used'tlley, become dried and consequently cause the rodsv to stick.A These stuffing-boxes are'alsc 'objectionable upon an apparatus ofthis sort inthat should they be tightened up too muchthey -will render'the apparatus in-a operative, thus permitting a disobedientjenggineer-or other mischievously inclinedgperson to put the apparatus out of. commisgful While I prefer avoiding the use of stuing bornes, it viiill be understood however that. v the invention in its broader aspect mayl loe carried into effect -with an apparatus in which stufling boxes are employed. It will' vbe observed also'that while I prefer "to use air as theluid motive power, I may in some cases emplcystearn or liquid Wit,houtdepartin from the spiritomy invention.

aving thus described my invention,vvl'iat I claim as new'and desire ters Patent, is'J v 1. In a train. stopping apparatus, a'brake.

to secure by Letf.

setting means, a differentlal uid pressure motor for actuating the brake setting and lalso for restoring the brake tting means to normal,v and a common iuif pressure-reservoir for causing both thesemovements, means being provided for constantly subjecting to reservoir pressure the `low pressure side ofthe piston tothereby nor-f mally `hold the brake setting. means inops erative.

2.'In a train stopping apparatus, 'brake setting means, a' differential fluid p essure motor for actuating the brake setting means and also'ior restoring thev brake setting' means to normal, and a common fluid pres,- sure reservoir for causing both'these move-v ments,l said motor embodyingv a differential main piston and a differential pilot valve de` `ance.

3. Ina train stopping apparatus a brake setting means', a differential Huid pressure motor for actuating the brake setting means and also v for restoring the brake setting memes means to normal, and a common fluid pressure reservoir for causing both these movements, said motor embodying a differential main piston and a differential pilot valve device, said pilot valve device embodying a 'ating said motor by main reservoiralr 1n both its opening and closing movements, means being provided for constantly subjectin to reservoir pressure the low pressure 15., si e of the piston to thereby normally hold the brake setting means inoperative.

5. In an automatic train stop, the combination of a vent valve in the train pipe, a pneumatic motor for positively opening and closing said valve and normally holding it closed, anda pneumatically controlled,

valve mechanism for reversing the normal action of the motor to thereby open the vent valve, this valve mechanism embodying means for holding its valve open by 4main air reservoir pressure.

6. In a train stopping apparatus, a valve for venting the train pipe, a motor for operating said valve consisting of a differential arrangement of pistons and cylinders, the cylinders both being normally open to main air reservoir pressure, and means for vent'- ing one of the cylinders to reverse the differential pressure on the piston therein to thereby cause the motor to operate said 'vent valve.

7. In a train stopping apparatus embodying a valve for venting the train pipe, means controlled by direct main reservoir air pressure for positively opening and closing said valve, said means embodying a motor cylinder, a. differential piston working therein and having its low pressure side connected to the venting valve, and means whereby reservoir pressure is constantly admitted to the low pressure side of the piston.

8. In a train stopping apparatus, the combination of a brake setting means, a main cylinder, a supplemental cylinder carried by one of the heads of the aforesaid cylinder, a differential piston working in said main cylinder, a rod connected to this piston and provided with a smaller pison-worlring in said supplemental cylinder, this smaller piston being connected to the brake setting means, means for transmitting fluid pressure to the opposite sides of said main piston, and valve mechanism for controlling the admiion and exhaust of fluid to and from said main cylinder.

9. In a train stopping apparatus, brake setting devices and fluid pressure means for positively actuating and restoring said brake setting devices, said means embodying a cylinder and differential piston, means connecting the piston to the brake setting devices, means whereb fluid pressure is constantly admitted to tlie side of lesser pressure of said piston, a pilot valve device for controlling admission of air to the other side of said piston and pneumatic'means or controlling this pilot valve device.

Intestimony whereof: I hereunto ax my signature in the presence of two witnesses.

v HIRAM G. SEDGWICK.

Witnesses:

C. D. Davis, CHARLES LOWELL HOWARD. 

